1. Field of the Invention
This invention relates to a method for producing novel candied fruit as well as dried fruit.
2. Related Art Statement
For processing natural fruits for producing the candied fruit (preserved fruit) with long shelf life, it is necessary that the pores or water contained in the fruit be substituted by a syrup, that is, sugar or saccharose solution. As a method for syrup substitution in this manner, it has been known to get the natural fruit immersed in a range of sugar solutions having their sugar concentration increasing sequentially from e.g. the Brix value of 25.degree. to make use of the osmotic presure to permeate the syrup into the fruit pulp, or to boil the natural fruit as it is immersed in the sugar solution.
However, these known methods are inconvenient in that the odor, flavor and tint proper to the natural fruit are lost. In the latter method, inter alia, prolonged processing time is required with the use of the osmotic pressure while, in some fruits, the sugar solution is not permeated sufficiently due to their specific textural composition.
In our Japanease Patent Publication No. 9377-1976, it has been proposed to produce a novel candied fruit having a long shelf life without loss of taste, odor or tint proper to natural fruit by substitution of the pores or water in the dipped fruit pulp by the sugar solution under reduced pressure. According to this proposed method, the natural fruit is washed with water, peeled and cored. The fruit thus processed is immersed in a vacuum tank in which the pressure is reduced for expelling air bubbles contained in the fruit pulp. The sugar solution or syrup is then injected into the tank maintained under reduced pressure. After the end of injection, the pressure within the tank is reset to the atmospheric pressure for permeating the syrup into the fruit pulp. By this proposed method, the processing time can be shortened as compared to the method of simply using the osmotic pressure, while the odor, taste and tint proper to the natural fruit are also kept to some extent.
However, when applied to processing of whole fruits, such as whole apple, to candied fruit, the above described proposed method including vacuum treatment gives rise to a number of inconveniences such that
(a) it is difficult to substitute the inside pores or water in the fruit pulp at one time by the sugar solution of a predetermined concentration;
(b) because of considerable volumetric changes encountered during the manufacture process, it is difficult to control the sugar content or concentration in the ultimate product;
(c) considerable syrup wastage is encountered; and
(d) the productive efficiency is also low on account of an excessive number of production steps.
On the other hand, when desired to dry the thus-obtained candied fruit for producing dried fruit, it is desired that the substitution syrup be rather high in sugar concentration for maintaining good taste of dried fruit. However, it is not possible with the conventional methods to substitute the inside pores or water in the fruit pulp with the syrup having the Brix value higher than 50.degree. and thus a prolonged drying time is required in order to reach the desired sugar content. In addition, the resulting dried fruit is generally poor in palatability or tint.